MAINTAINERS: replace an AT91 maintainer

As some help is needed from an active maintainer, replace Andrew Victor
by Alexandre Belloni in the ARM/Atmel MAINTAINERS' entry (aka AT91).
Add an entry to the CREDITS file.

Thanks Andrew for the great role you played during the early days of this
product family.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Andrew Victor <linux@maxim.org.za>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
diff --git a/CREDITS b/CREDITS
index 40cc4bf..ec7e6c7f 100644
--- a/CREDITS
+++ b/CREDITS
@@ -3709,6 +3709,13 @@
 D: Co-author of German book ``Linux-Kernel-Programmierung''
 D: Co-founder of Berlin Linux User Group
 
+N: Andrew Victor
+E: linux@maxim.org.za
+W: http://maxim.org.za/at91_26.html
+D: First maintainer of Atmel ARM-based SoC, aka AT91
+D: Introduced support for at91rm9200, the first chip of AT91 family
+S: South Africa
+
 N: Riku Voipio
 E: riku.voipio@iki.fi
 D: Author of PCA9532 LED and Fintek f75375s hwmon driver